Solid-state drives (SSDs, also known as a solid-state disks) are a class of storage devices that may use integrated circuit assemblies as memory to store data persistently. SSDs may have better read/write performance compared to hard disk drives (HDDs). SSDs may be used in storage arrays to provide high performance scale-out storage.
SSDs can experience “hiccups” (or “stutters”) which adversely affect read and/or write operations. Hiccups may occur due to internal SSD processing, such as garbage collection. In general, it is difficult (if not impossible or at least impractical) to predict when hiccups will occur. Hiccups can increase the latency of read and write operations, adversely affecting system performance.
As is also known in the art, RAID (Redundant Array of Inexpensive/Independent Disks) is a concept designed to provide increased resiliency and reliability to storage arrays. It allows reconstruction of failed disks (and parts of disks) through the use of redundancy. RAID 6 defines block-level striping with double distributed parity (N+2) and provides fault tolerance of two drive failures, so that a storage array can continue to operate with up to two failed drives, irrespective of which two drives fail. To provide efficient reads, data is stored “in the clear,” whereas parity information can be based on a suitable coding scheme.